Nuclear physics

Heaviest known element has electrons that break the mould

Oganesson nuclei are bathed in an electron haze.

Electrons generally orbit atomic nuclei in distinct shells, but calculations show that the outer electrons of oganesson, the heaviest element found so far, may instead orbit the nucleus as a gas.

Oganesson decays quickly, making it a challenge to probe experimentally. Instead, Peter Schwerdtfeger at Massey University Auckland in New Zealand and his colleagues calculated the energy levels of electrons around oganesson nuclei. For greater accuracy, the researchers took into account what are known as ‘relativistic effects’ — the influence of the element’s high nuclear charge, which is much greater than that of lighter elements.

The team found that in oganesson, the outermost electron orbits become indistinct, creating an outer layer that is almost an electron gas. Oganesson is classified as a noble gas, but the findings suggest that it may behave differently from other members of its group and may even be solid at room temperature.